title: Transmit gain calibration for nonproton MR using the Bloch-Siegert shift.
abstract: Transmit gain (B 1+) calibration is necessary for the adjustment of radiofrequency (RF) power levels to the desired flip angles. In proton MRI, this is generally an automated process before the actual scan without any user interaction. For other nuclei, it is usually time consuming and difficult, especially in the case of hyperpolarised MR. In the current work, transmit gain calibration was implemented on the basis of the Bloch-Siegert phase shift. From the same data, the centre frequency, line broadening and SNR could also be determined. The T(1) and B(0) insensitivity, and the wide range of B 1+ over which this technique is effective, make it well suited for nonproton applications. Examples are shown for hyperpolarised (13)C and (3)He applications.
authors.affiliation: GE Global Research, Munich, Germany. Rolf.Schulte@research.ge.com
authors.forename: Rolf F
authors.initials: RF
authors.lastname: Schulte
authors.forename: Laura
authors.initials: L
authors.lastname: Sacolick
authors.forename: Martin H
authors.initials: MH
authors.lastname: Deppe
authors.forename: Martin A
authors.initials: MA
authors.lastname: Janich
authors.forename: Markus
authors.initials: M
authors.lastname: Schwaiger
authors.forename: Jim M
authors.initials: JM
authors.lastname: Wild
authors.forename: Florian
authors.initials: F
authors.lastname: Wiesinger
mesh_terms: D002138:Calibration; D002247:Carbon Isotopes; D006371:Helium / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011522:Protons; D015203:Reproducibility of Results
chemical_list: D002247:Carbon Isotopes; D011522:Protons; D006371:Helium; D019344:Lactic Acid